JP2010530133A - Structure of surface treatment layer of multilayer substrate and manufacturing method thereof - Google Patents

Abstract

The structure of the surface treatment layer of the multilayer substrate includes a pad layer, at least one covering metal layer, and a solder mask layer. The pad layer is embedded in the dielectric layer. At least one coated metal layer covers the pad layer. The solder mask layer has an opening that exposes at least one coated metal layer. In the present invention, a coating metal layer is first formed on the pad layer surface, and then a solder mask layer is formed. Thereafter, a solder mask layer is opened with respect to the position of the covering metal layer to expose the covering metal layer. Since the pad layer of the present invention is embedded in the dielectric layer, the adhesion force between the pad layer and the dielectric layer can be increased. At the same time, since the solder mask layer covers part of the coated metal layer, contact between the tin material or other solder and the pad layer can be avoided when packaging.

Description

The present invention relates to a structure of a surface treatment layer of a multilayer substrate and a manufacturing method thereof, and more particularly to a structure of a surface treatment layer of a flexible multilayer substrate and a method of manufacturing the same.

The conventional surface finish of a multilayer board can be divided into two types, a pad layer definition (Pad Definition) method and a solder mask layer definition (Solder Mask Definition) method.

The conventional technique shown in FIG. 1 is a surface finish structure (surface finish structure) surface-treated by a pad layer definition method. In the conventional technique, after a pad layer (Pad) 101 is formed on a dielectric layer, a solder mask layer 104 (Solder Mask) is applied. Thereafter, a hole is formed at the position of the pad layer 101, and a descum step is provided to remove the rubber scraps remaining on the pad layer 101. Finally, a nickel metal layer 102 and a gold metal layer 103 are formed on the pad layer 101.

The conventional technique shown in FIG. 2 is a structure of a surface treatment layer surface-treated by a solder mask layer definition method. After the pad layer 101 is formed on the dielectric layer, the solder mask layer 104 is applied. Thereafter, a hole is formed at the position of the pad layer 101, and a descum step is provided to remove the rubber scraps remaining on the pad layer 101. Finally, a nickel metal layer 102 and a gold metal layer 103 are formed on the pad layer 101 again. Unlike the pad layer definition method, the opening area of the pad layer definition method includes the entire area occupied by the pad layer 101, but the solder mask layer definition method is such that the solder mask layer 104 covers a part of the pad layer 101. To.

In both the pad layer definition method and the solder mask layer definition method, a step of forming a plurality of coated metal layers is always performed after the application and opening of the solder mask layer 104. When the subsequent element is packaged in a general pad layer 101 made of copper as a material, the element and the pad layer 101 are bonded and packaged using a tin material or other solder. However, the contact of the tin material or other solder with copper causes melting development, so the purpose of coating the metal layer is to avoid contact of the tin material or other solder with copper. However, the above-described pad layer definition or solder mask layer definition method is based on the moisture generated in the environment or the stress generated by the coating metal layer, the dielectric layer, and the solder mask layer being different from each other. 1 or 2 indicates that there is a possibility of delamination, and when tin or other solder is brought into contact with the pad layer 101, melting occurs and an intermetallic compound (IMC) is generated. As a result, the contact structure becomes fragile and the reliability of the product decreases.

In addition, since all of the pad layer 101 is formed on the surface of the dielectric layer regardless of the definition method of the pad layer or the solder mask layer, there is a possibility that the pad layer 101 is peeled off or separated, and the reliability of the package Decreases.

Therefore, even when packaging, avoid contact between the tin material or other solder and the pad layer, and if the pad layer strengthens the adhesion to the lower dielectric layer, the reliability of the package and the yield rate of the package product are improved. can do.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a structure of a surface treatment layer of a multi-layer substrate and a method of manufacturing the same, in which a pad layer is embedded in a dielectric layer to avoid peeling of the pad layer or interlayer separation and to improve package reliability. This is the issue.

  Another object of the present invention is to manufacture the coated metal layer first before forming the solder mask layer, and when packaging, avoid contact between the tin material or other solder and the pad layer. It is an object of the present invention to provide a structure of a surface treatment layer of a multilayer substrate that improves reliability and a manufacturing method thereof.

In order to achieve the above object, the structure of the surface treatment layer of the multilayer substrate of the present invention includes a pad layer, at least one covering metal layer, and a solder mask layer. The pad layer of the present invention is embedded in the dielectric layer of the multilayer substrate, and the covering metal layer covers the pad layer. The solder mask layer has an opening that exposes the coating metal layer. In the present invention, the mask layer is formed after forming the covering metal layer on the surface of the pad layer. Thereafter, a solder mask layer is opened with respect to the position of the covering metal layer to expose the covering metal layer.

Although the pad layer of the present invention can be formed on the surface of the dielectric layer, the covering metal layer is first formed on the surface of the pad layer, and then the mask layer is formed. Thereafter, a solder mask layer is opened to the position of the covering metal layer to expose the covering metal layer.

The present invention also provides a method for manufacturing the structure of the surface treatment layer of a multilayer substrate. The manufacturing method of the present invention includes a step of forming a covering metal layer covering the entire pad layer on the surface of the pad layer, a step of forming a solder mask layer on the surface of the multilayer substrate including the pad layer, and a position of the covering metal layer. Opening a solder mask layer to expose the covering metal layer. The pad layer of the present invention is embedded in the surface of the dielectric layer of the multilayer substrate or formed on the surface of one dielectric layer of the multilayer substrate.

Compared with the prior art, the structure of the surface treatment layer of the multilayer substrate of the present invention embeds the pad layer in the dielectric layer, so that the adhesion force between the pad layer and the dielectric layer can be increased, and the pad layer and the dielectric layer The layer is easily peeled off and not delaminated, increasing the reliability. And before forming the solder mask layer, firstly, a coated metal layer is manufactured and used as a barrier layer between the tin material or other solder and the pad layer, for moisture present in the environment, or Also due to the stress between the coated metal layer and the dielectric layer and the solder mask layer, even when causing delamination between the coated metal layer and the dielectric layer, or between the coated metal layer and the solder mask layer, tin or other The reliability of the package can be improved by ensuring that the contact between the solder and the pad layer is avoided.

The structure of the surface treatment layer (Surface Finish) by the pad layer definition (Pad Definition) method in the prior art is shown. The structure of the surface treatment layer by the solder mask definition method in the prior art is shown. The schematic of the 1st Example of the structure of the surface treatment layer of the multilayer substrate in this invention is shown. The schematic of the 2nd Example of the structure of the surface treatment layer of the multilayer substrate in this invention is shown. The schematic of the 3rd Example of the structure of the surface treatment layer of the multilayer substrate in this invention is shown. The schematic of the 4th Example of the structure of the surface treatment layer of the multilayer substrate in this invention is shown. 3 shows a flowchart of a method for manufacturing the structure of the surface treatment layer of the multilayer substrate of the first embodiment according to the present invention. 3 shows a flowchart of a method for manufacturing the structure of the surface treatment layer of the multilayer substrate of the first embodiment according to the present invention. 4 shows a flowchart of a method for manufacturing a structure of a surface treatment layer of a multilayer substrate of a third embodiment according to the present invention. 4 shows a flowchart of a method for manufacturing a structure of a surface treatment layer of a multilayer substrate of a third embodiment according to the present invention.

The above and other objects, features, and advantages of the present invention will be described in detail with reference to the accompanying drawings so that the present invention can be understood more clearly.

FIG. 3 shows a schematic diagram of the first embodiment of the structure of the surface treatment layer of the multilayer substrate in the present invention. The pad layer 301 (Pad) of the present invention is embedded in a dielectric layer. The dielectric layer material can be polyimide. In the first embodiment of the present invention, first, a plurality of coating metal layers, that is, a nickel coating metal layer 302 and a gold coating metal layer 303 are formed on the pad layer 301. Thereafter, the solder mask layer 304 is formed, and the solder mask layer 304 is opened at the position of the gold-coated metal layer 303 to expose the gold-coated metal layer 303. A portion of the nickel-coated metal layer 302 and the gold-coated metal layer 303 is covered.

Since the pad layer 301 is embedded in the dielectric layer, the adhesion between the pad layer 301 and the dielectric layer can be increased, and the pad layer 301 and the dielectric layer are not easily delaminated. Increase confidence. The solder mask layer 304 is covered with a nickel-coated metal layer 302 and a gold-coated metal layer 303 by a solder mask layer definition (Solder Mask Definintion) method so that the nickel-coated metal layer is covered. 302, even when the metal covering metal layer 303 is wet or stressed and the interlayer separation occurs between the solder mask layer 304 or the dielectric layer, the tin material or other solder and the pad layer 301 Ensuring separation of contact between the two improves the reliability of the package.

FIG. 4 shows a schematic diagram of the second embodiment of the structure of the surface treatment layer of the multilayer substrate in the present invention. As in the first embodiment, the pad layer 401 of the present invention is embedded in a dielectric layer. Since this second embodiment is a method of defining a solder mask layer, after the solder mask layer 404 is formed, the solder mask layer 404 is opened to the position of the pad layer 401 to expose the pad layer 401. The solder mask layer 404 covers a part of the pad layer 401. A plurality of coating metal layers, that is, a nickel coating metal layer 402 and a gold coating metal layer 403 are formed on the pad layer 401.

The difference from the conventional technique shown in FIG. 2 is that the pad layer 401 is embedded in the dielectric layer, so that the adhesive force between the pad layer 401 and the dielectric layer can be increased. Increases reliability by not separating.

FIG. 5 is a schematic view of a third embodiment of the structure of the surface treatment layer of the multilayer substrate in the present invention. As in the first embodiment, the pad layer 501 having the structure of the surface treatment layer of the multilayer substrate of the present invention is embedded in the dielectric layer. Since this third embodiment is based on the pad layer definition (Pad Definition) method, this embodiment first includes a plurality of coating metal layers on the pad layer 501, that is, a nickel coating metal layer 502 and a gold coating metal layer 503. Form. Subsequently, a solder mask layer 504 is formed, and the solder mask layer 504 is opened at the position of the pad layer 501 to expose the gold-coated metal layer 503. The area of the opening includes the area occupied by the pad layer 501 and is larger than the area occupied by the pad layer 501. Alternatively, in this embodiment, the solder mask layer 504 is first formed, the solder mask layer 504 is opened at the position of the pad layer 501, and then the nickel-coated metal layer 302 and the gold-coated metal layer. 303 may be formed.

1 differs from the prior art shown in FIG. 1 because the pad layer 301 is embedded in the dielectric layer, the adhesion between the pad layer and the dielectric layer can be increased, and the pad layer and the dielectric layer can be easily separated from each other. As a result, reliability is improved.

FIG. 6 shows a schematic diagram of the fourth embodiment of the structure of the surface treatment layer of the multilayer substrate in the present invention. The pad layer 601 is formed on the surface of the dielectric layer. In the fourth embodiment, the present invention first forms a plurality of coating metal layers on the pad layer 601, that is, a nickel coating metal layer 602 and a gold coating metal layer 603. Further, after forming the solder mask layer 604, the solder mask layer 604 is opened at the position of the gold-coated metal layer 603 to expose the gold-coated metal layer 603, and the solder mask layer 604 is Part of the nickel-coated metal layer 602 and the gold-coated metal layer 603 is covered.

Since the solder mask layer 604 of the present invention covers the nickel-coated metal layer 602 and a part of the gold-coated metal layer 603, the nickel-coated metal layer 602, the gold-coated metal layer 603, and the solder mask Even when interlayer separation occurs between the layer 604 or the dielectric layer, it is possible to ensure that contact between the tin material or other solder and the pad layer 601 is avoided, thereby improving the reliability of the package. .

7A to 7E show a method flowchart for manufacturing the structure of the surface treatment layer of the multilayer substrate of the first embodiment shown in FIG. 3 according to the present invention. FIG. 7A shows that the pad layer 301 is first formed on the surface of the temporary substrate 700 and the interfacial adhesion strengthening process 305 is performed. The interfacial adhesion strengthening process 305 is, for example, an oxygen or argon plasma process. FIG. 7B shows the formation of a dielectric layer 702 that covers the entire substrate 700. In FIG. 7C, after the dielectric layer 702 and the pad layer 301 are separated from the surface 700 of the substrate and turned upside down, a nickel-coated metal layer 302 and a gold-coated metal layer 303 are formed on the surface of the pad layer 301. The pad layer 301 is covered. FIG. 7D shows the formation of a solder mask layer 304 that covers the entire gold coated metal layer 303 and dielectric layer 702. In FIG. 7E, the solder mask layer 304 is opened at the positions of the nickel-coated metal layer 302 and the gold-coated metal layer 303 to expose the gold-coated metal layer 303, and the solder mask layer 304 is exposed. Covers a part of the gold-coated metal layer 303, that is, the pad layer 301 is embedded in the surface treatment layer of the dielectric layer 702, and the solder mask layer 304 is a part of the gold-coated metal layer 303. The structure which covers a part is implement | achieved. However, also in the third embodiment shown in FIG. 5 of the present invention, the pad layer 501 can be formed by the same method, and the area of the opening includes the area occupied by the pad layer 301 when opening in FIG. 7E. And the area occupied by the pad layer 301 is preferably larger. For example, if the pad layer 401 in the second embodiment shown in FIG. 4 of the present invention is to be formed, the order of steps in FIGS. 7C and 7D is changed, that is, the solder mask layer 304 is first formed to open the holes. Then, after the solder mask layer 304 covers a part of the pad layer 301, the nickel-coated metal layer 302 and the gold-coated metal layer 303 may be formed.

8A to 8E show a flowchart of a method for manufacturing the structure of the surface treatment layer of the multilayer substrate of the third embodiment shown in FIG. 5 according to the present invention. FIG. 8A shows that a solder mask layer 504 is first formed on the surface of the substrate 800. FIG. 8B shows that a pad layer 501 is first formed on the surface of the solder mask layer 504, and a dielectric layer 802 is formed, and an interfacial adhesion strengthening treatment 505 between the pad layer 501 and the dielectric layer 802, for example, oxygen or Indicates that the argon plasma process will be performed. FIG. 8C shows that the solder mask layer 504 is separated from the surface of the substrate 800 and flipped up and down so that the solder mask layer 504 faces up so as to open the solder mask layer 504. 8D, the solder mask layer 504 is opened at the position where the pad layer 501 is embedded to expose the pad layer 501, and the area of the opening in FIG. 8D includes the area occupied by the pad layer 501 and the pad. It indicates that the area is larger than the area occupied by the layer 501. FIG. 8E shows that the pad layer 501 is coated by forming a nickel-coated metal layer 502 and a gold-coated metal layer 503 on the surface of the pad layer 501. That is, a structure in which the pad layer 501 is embedded in the surface treatment layer of the dielectric layer 802 can be realized. However, also in the second embodiment shown in FIG. 4 of the present invention, the pad layer 401 can be formed by the same method. When the hole is opened in FIG. 8D, the solder mask layer 504 forms a part of the pad layer 501. You may make it cover.

In the first to fourth embodiments of the present invention, the interfacial adhesion strengthening treatments 305, 405, 505 and 605 are performed between the pad layers 301, 401, 501 and 601 and the dielectric layer, and the pad is formed. Increase the adhesion strength between the layers 301, 401, 501, and 601 and the dielectric layer. Furthermore, peeling or delamination of the pad layers 301, 401, 501, and 601 can be avoided.

Finally, since the present invention uses a substrate to manufacture a pad layer embedded in a dielectric layer, the adhesion between the pad layer and the dielectric layer can be increased, avoiding peeling or delamination of the pad layer. , Strengthen the reliability. At the same time, before forming the solder mask layer, the coated metal layer is first manufactured, so that the solder mask layer covers a part of the coated metal layer, due to moisture or stress, the coated metal layer and the solder mask layer Alternatively, even when interlayer separation occurs between the dielectric layer and the dielectric layer, the reliability of the package can be improved by ensuring that the contact between the tin material or other solder and the pad layer is avoided. Therefore, the reliability of the multilayer substrate package and the yield rate of the package product can be improved.

Although preferred embodiments of the present invention have been disclosed above, as those skilled in the art can appreciate, they are not intended to limit the invention in any way. Various changes and modifications can be made without departing from the spirit and scope of the present invention. Accordingly, the scope of the claims of the present invention should be construed broadly including such changes and modifications.

101, 301, 401, 501, 601: Pad layer 104, 304, 404, 504, 604: Solder mask layer 102: Nickel metal layer 103: Gold metal layer 302, 502, 602: Nickel coated metal Layers 303, 503, 603: Gold coated metal layers 305, 405, 505, 605: Interfacial adhesion strengthening treatment 700, 800: Substrate 702, 802: Dielectric layer

Claims (29)

The structure of the surface treatment layer of the multilayer substrate,
A surface treatment of a multilayer substrate, comprising: a pad layer embedded in a dielectric layer; at least one coating metal layer covering the pad layer; and a solder mask layer having an opening exposing the coating metal layer Layer structure. The structure according to claim 1, wherein the solder mask layer covers a part of the covering metal layer. The structure according to claim 1, wherein an area of the opening includes an area occupied by the covering metal layer. The structure according to claim 1, wherein the coating metal covers the pad layer after forming an opening in the solder mask layer. The structure of claim 4, wherein the solder mask layer covers a part of the pad layer. The structure of claim 1, wherein the dielectric layer material is polyimide. The structure of claim 1, wherein the pad layer material is copper. The structure of claim 1, wherein the coated metal layer is nickel. The structure of claim 1, wherein the covering metal layer is gold. The structure according to claim 1, wherein an interfacial adhesion strengthening process is performed between the pad layer and the dielectric layer to increase adhesion strength between the pad layer and the dielectric layer. A structure of a surface treatment layer of a multilayer substrate, comprising: a pad layer formed on a surface of a dielectric layer; at least one covering metal layer covering the pad layer; and a solder mask layer covering a part of the covering metal layer The structure of the surface treatment layer of the multilayer substrate characterized by including. The structure according to claim 11, wherein an adhesion strength between the pad layer and the dielectric layer is increased by performing an interfacial adhesion strengthening process between the pad layer and the surface of the dielectric layer. The structure of claim 11, wherein the dielectric layer material is polyimide. The structure of claim 11, wherein the material of the pad layer is copper. The structure of claim 11, wherein the coated metal layer is nickel. The structure of claim 11, wherein the covering metal layer is gold. A method of manufacturing a structure of a surface treatment layer of a multilayer substrate,
Forming at least one covering metal layer covering the entire pad layer on the surface of the pad layer;
Forming a solder mask layer on the surface of the multilayer substrate with the pad layer;
Opening the solder mask layer with respect to the position of the covering metal layer, and exposing the covering metal layer. The manufacturing method according to claim 17, wherein the solder mask layer covers a part of the covering metal layer. The manufacturing method according to claim 17, wherein an area for opening the solder mask layer includes an entire area occupied by the covering metal layer. The manufacturing method according to claim 17, further comprising a step of embedding the pad layer in a dielectric layer of the multilayer substrate before the step of forming the covering metal layer. The step of embedding the pad layer in the dielectric layer of the multilayer substrate includes first forming the pad layer on the surface of the temporary substrate, and forming the dielectric layer, and then combining the dielectric layer and the pad layer with the temporary layer. 21. The manufacturing method according to claim 20, wherein the pad layer is embedded in the dielectric layer separately from the surface of the substrate. The method according to claim 17, further comprising forming the pad layer on the surface of the dielectric layer of the multilayer substrate before the step of forming the covering metal layer. A method of manufacturing a structure of a surface treatment layer of a multilayer substrate,
Forming a solder mask layer;
Opening the solder mask layer with respect to the position of the pad layer embedded in the surface of the dielectric layer of the multilayer substrate, exposing the pad layer;
Forming a surface treatment layer structure of a multilayer substrate, comprising: forming at least one covering metal layer covering the pad layer on the surface of the pad layer. The manufacturing method according to claim 23, wherein the solder mask layer covers a part of the pad layer. The manufacturing method according to claim 23, wherein an area of the solder mask layer that is opened includes an area occupied by the pad layer. Before the step of forming the solder mask layer, the pad layer is first formed on the surface of the temporary substrate, and after the dielectric layer is formed, the dielectric layer and the pad layer are removed from the surface of the substrate. 24. The method of claim 23, further comprising separating the pad layer so as to be embedded in the dielectric layer. The method according to claim 23, wherein the solder mask layer is first formed on a surface of a substrate. After the step of forming the solder mask layer on the surface of the substrate, the pad layer is first formed on the surface of the solder mask layer, and after the dielectric layer is formed, the pad layer is embedded in the dielectric layer. The method according to claim 27, further comprising the step of: 28. The manufacturing method according to claim 27, further comprising the step of separating the solder mask layer from the surface of the substrate before the step of opening the solder mask layer.

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